Opinions on these previously mentioned 148/Grant mods

[Big Kahuna]

I was looking back at some modifications mentioned the forum and was wondering on opinions from those that have tried them. Many were mentioned but there weren't a lot of responses from people who have tried them (unlike our excellent Schottky diode thread).

I've always left Grant's stock for the most part but thought these were interesting.

# 1 Increased modulation all modes

1K series resistor on the middle leg of TR24, and change R124 and R126 to 4.7K

# 2 Motor Mouth HIFI RX Mod

http://www.motormouthmaul.com/linked/cobra 148 rx mod.pdf

# 3 TX HIFI Mod

C46 Change to 2.2uf mylar/polyester film or non-polarized electrolytic

C101 Change to 1.5uf tantalum 16 to 50 volt

C102 Change to a 910pf ceramic disc

C104 Change to 2.2uf tantalum 16 to 50 volt

C108 Change to 1uf to 2.2 uf tantalum 16 to 50 volt

I found that if you have a very deep voice start with 1uf on C108 and work up if need be.

If you need more highs on tx Change C 105 to .001 to .0001uf mylar/polyester film The smaller you go the more highs you get.

 

[red97k1500]

I’m by no means a tech or expert, but from my personal experience I wouldn’t recommend doing the mmm high fi rx or any revive mod for that matter, it seriously screwed up the receive on upper and lower sideband on the radio I tried it on.

 

[711]

MMM hifireceive mod is fine, the other TX mods works also. I normally do audio widening on all my radios.